JPS645185B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a valve sealing device used to completely shut off or allow fluid flowing in piping.

(Prior Art) Conventionally, in fluid cutoff valves that use synthetic resin as a sheet pankin for fluid cutoff, many different shapes and materials have been used to prevent permanent deformation of the synthetic resin and to improve fluid cutoff performance. An example of a conventional "unfixed sealing device" that uses a valve seal (Japanese Patent Application Laid-Open No. 51-77923, Figure 4)
As shown in FIG. 1, a synthetic resin seat packing 31 that is relatively easily deformed is tightened between a valve body 32 and a seat packing retainer 33, and the outer edge of the seat packing 31 has a sealing lip 34. The free end of the lip 34 seals a wedge-shaped space formed in the valve body 32, and the lip 34 can be moved relatively freely, with a part of the convex surface being supported by the valve body 32. , a metal annular member 3 having a roughly V-shaped cross section in order to avoid deformation of the lip that abuts with a pressing force on the periphery of the inner valve 35.
6 is inserted into the concave surface, and when pressurized from the concave surface side, the seat gasket 31 other than the lip is inserted into the valve body 32.
At this time, as the pressure increases, the sealing pressure against the periphery of the inner valve 35 increases, and when it increases toward the convex surface, the pressure passes through the surface groove 37 provided in the support of the valve body 32 and connects with the valve body 32. It enters between the seat packing 31 and generates a force in the biasing direction 38 toward the concave surface of the seat packing, thereby increasing the sealing pressing force between the lip 34 and the valve seat surface 39 of the inner valve 35.

(Problems to be Solved by the Invention) In this conventional sealing device, there are many parts of the sheet gasket that protrude into the flow path, and in high-pressure fluid, the end of the sheet gasket on the flow path side is permanently deformed. There have been problems in that the metal annular member may fall off from the seat packing, resulting in a reduction in sealing performance.

It is an object of the present invention to provide a self-adjusting elastic sheet packing that solves the above-mentioned problems and completely blocks fluid regardless of the flow direction of the fluid with respect to the sealing device, has excellent durability, and can maintain initial performance for a long period of time. An object of the present invention is to provide a valve sealing device according to the method.

(Means for Solving Problems) The gist of the present invention is to provide protrusions 14, 14 facing each other at the groove outlet by the valve body 2 and the seat packing retainer 3 around the flow path of the valve body. A synthetic resin sheet packing 1 having an approximately T-shaped cross section is configured in an annular manner, with an approximately T-shaped groove formed in an annular shape, and a protrusion limiting shoulder 12 that can be engaged with the protrusion 14 is formed into an annular shape. An approximate V-shaped groove is loosely fitted in the groove, and an approximate V-shaped groove is formed between the sheet gasket 1 and the sheet gasket presser 3 on the sheet gasket presser side of the synthetic resin sheet gasket 1 with a clearance 8 interposed therebetween. The V is formed in the sheet packing so that there is an opening.
A first fluid pressure introducing chamber 9 is provided by inserting an annular metal elastic member 6 having a doglegged bent portion 17 inscribed in the shaped groove, and on the opposite side there is provided a first fluid pressure introduction chamber 9 between the seat packing 1 and the valve body 2. In a valve sealing device in which a second fluid pressure introducing chamber 10 is provided through a clearance 8', and an inner valve 4 is brought into contact with a portion of the seat packing 1 that protrudes into the flow path so as to be able to freely approach and separate, the above approximation is applied. At a portion of the outer peripheral inner wall surface 15 of the T-shaped groove closer to the sheet packing presser 3, the sealing surface 13, which is a part of the outer peripheral wall of the outer peripheral portion 28 of the seat packing 1, comes into close contact, thereby introducing the second fluid pressure. A small gap constituting a part of the chamber 10 exists between the outer circumferential inner wall 15 and the seat packing holder 3 only at a location farthest from the seat packing holder 3. An outer flange portion 16 is provided between the sheet packing presser 3 and the sheet packing holder 3, and extends from the doglegged bent portion 17 to the outer end of the sheet packing 1.

The present invention has thus been able to solve the problems of the prior art and achieve the object.

(Embodiment) FIG. 2 shows an annular configuration of an approximately T-shaped groove in cross section with protrusions 14, 14 facing each other at the groove outlet formed around the flow path of the valve body 2 by the valve body 2 and the seat packing retainer 3. A synthetic resin sheet packing 1 having an approximately T-shaped cross section and provided with protrusion limiting shoulders 12, 12 that engage with the protrusions 14, 14 is formed into an annular shape, and is inserted into the groove so as to be slightly movable.
This figure shows an embodiment in which an annular metal elastic member 6 is fitted into an approximate V-shaped groove, and shows a state in which the inner valve 4 is not yet in contact with the seat packing 1. Also,
The part indicated by the two-dot chain line indicates the position of the inner valve 4 when the flow path is blocked.

FIG. 3 shows a state in which the inner valve 4 actually blocks the flow path in the state shown in FIG. 2. Here, the seat packing 1 and the metal elastic member 6 are installed in a groove having an approximately T-shaped cross section formed in a direction perpendicular to the flow path, and the seat packing 1 is connected to the valve seat surface 5 of the inner valve 4. The contact surface 11 of the valve is formed into an inclined surface, and protrusion limiting shoulders 12 are provided on both sides of the contact surface 11 to prevent protrusion toward the flow path. A second fluid pressure introducing chamber 10 is provided for pressure balance with the flow path side through a clearance 8' for introducing the fluid, and a second fluid pressure introducing chamber 10 is provided for pressure balance with the flow path side. An approximate V-shaped groove is formed to open in the direction of the sheet packing presser 3 through a clearance 8 for introducing fluid pressure therebetween;
A space of a first fluid pressure introduction chamber 9 is formed by fitting a metal elastic member 6 into this approximate V-shaped groove. The metal elastic member 6 has an outer flange portion 16 inserted between the seat packing 1 and the seat packing presser 3, and the approximate V-shaped groove formed between the seat packing 1 and the seat packing presser 3 following the outer flange portion 16. It is made of a single sheet of metal that continuously forms a dogleg-shaped curved portion 17 inside.

Figures 4 and 5, and Figures 7 and 8 show some embodiments.

In the embodiment shown in FIG. 4, 21 is a valve shaft that passes through a through hole provided in the inner valve 4 and a through hole bored in the valve body 2, and 22 is used to fix the valve shaft 21 and the inner valve 4. The pin 23 is a seal ring that prevents fluid from leaking to the outside of the valve body 2, and 24 is a lever handle that manually rotates the inner valve 4 up to 90 degrees to open or close the flow path or adjust the opening to any desired degree. , 25 are pins for fixing the valve shaft 21 and the lever handle 24.

(Operation) Next, the sealing operation of the valve sealing device of the present invention will be explained in detail with reference to FIGS. 2, 3, and 6.

First, from the state shown in Fig. 2, as shown in Fig. 3,
When the inner valve 4 is operated manually or by an automatic operating device using pneumatic pressure, hydraulic pressure, electricity, etc. to a position where the flow path is cut off, the inclined valve seat of the inner valve 4 is formed on the inclined contact surface 11 of the seat packing 1. Surface 5 is in contact. Due to this action, the sheet packing 1 is pushed and compressed in the direction opposite to the flow path side, and the metal elastic member 6 is also pushed at the same time, increasing the repulsive force of the metal elastic member 6 against the sheet packing 1. An initial pressure contact force is generated between the valve seat surface 5 of the inner valve 4 and the contact surface 11 of the seat packing 1 due to the restoring force of the seat packing. Next, when the inner valve 4 is placed in a state in which the flow path is opened, that is, the valve seat surface 5 is separated from the contact surface 11 of the seat packing 1, the seat packing 1 returns to the state shown in FIG. 2 due to the elastic force of the metal elastic member 6. .

In the sealing device of the present invention, by using fluid pressure, it is possible to maintain the contact surface pressure most suitable for the fluid pressure, so it is possible to stably shut off fluids from low pressure to high pressure fluids. be.

Next, a case where fluid pressure is applied will be explained.

Now, when the flow direction of the fluid is in the direction of arrow 30 in FIG.
Move a small amount in the same direction as 0. Since the inner valve 4 closes the flow path, the fluid pressure passes through the clearance 8 and reaches the first fluid pressure introduction chamber 9. At this time, the lower piece 18 of the metal elastic member 6 and the V of the seat packing 1
Pressure fluid flows in between the lower wall surface 27 of the groove and pressure is increased on the lower wall surface 27 of the seat gasket 1.
Press the inner peripheral part 29 of the inner valve 4 toward the contact surface 11
The contact surface pressure between the inner valve 4 and the valve seat surface 5 is increased. This increases the pressure of the inner valve 4 against the seat packing 1, increasing the contact surface pressure of the sealing surface 13 which is the contacting surface with the valve body 2 on the opposite side of the contact surface 11, completely blocking the fluid. can do. Due to the action of fluid pressure, a force is generated in the seat packing 1 that counters the force of the inner valve 4 trying to compress the seat packing 1, so that no abnormal concentrated load is applied to the seat packing 1, and the seat packing 1 is permanently compressed. Deformation can be prevented. In addition, in FIG. 3, when the flow direction of the fluid is opposite to the direction of the arrow 30, when the inner valve 4 blocks the flow path, the fluid pressure passes through the clearance 8' and enters the second fluid pressure introduction chamber. 10, the seat seal 1 is pushed in the direction of the flow path, increasing the contact surface pressure between the contact surface 11 of the seat seal 1 and the valve seat surface 5 of the inner valve 4, and at the same time, the seat seal 1 and the seat seal presser 3 and Since a pressing force is generated against the outer flange portion 16 of the metallic elastic member 6 inserted therebetween, the contact surface pressure of this portion is increased and the fluid can be completely shut off. In this case, as in the case where the fluid direction is in the direction of the arrow 30, a force is generated in the seat packing 1 due to the action of the fluid pressure that counters the force of the inner valve 4 trying to compress the seat packing 1. No abnormal concentrated load is applied to the seat packing 1, and permanent deformation of the seat packing 1 can be prevented.

The most suitable material for the sheet packing 1 is a resin with excellent wear resistance such as tetrafluoroethylene, but when using a synthetic resin with low mechanical strength,
As shown in FIG. 7, by inserting both side surfaces of the seat packing 1 into the approximate T-shaped groove in a state in which they are in close contact with each other, the width of the clearance 8, 8' between the approximate T-shaped groove and both side surfaces of the seat packing 1 is increased. In this case, the fluid pressure introduction hole 2 is integrated with the valve body 2 to strengthen the mechanical strength, as shown in the other embodiments shown in FIGS. 7 and 8.
6 and 26' on both sides of the seat packing 1, it is possible to completely shut off fluid by utilizing fluid pressure, as explained in FIG. 3 above.

Note that the above configuration of the present invention is applicable to the sheet packing 1.
The sealing surface 13 of the outer circumferential portion 28 has the effect of always maintaining the "initial pressure contact force" against the outer circumferential inner wall surface 15, and this further promotes the above-mentioned blocking effect (sealing effect). The above-mentioned "initial pressure contact force" will now be explained.

Japanese Patent Application Laid-Open No. 5177923 cited as the above-mentioned prior art
In "non-fixed sealing devices" including the one shown in Figure 4 of the issue, the circular fitting groove on the valve body side into which the annular seat packing is to be fitted has a diameter that is smaller than the inner diameter of the seat packing. When the outer diameter of the seat gasket is made slightly larger and the seat gasket is tightly fitted into the circular fitting groove, the seat gasket is compressed slightly and the outer periphery of the seat gasket is pressed against the inner wall surface of the circular fitting groove in the valve body. It turns out that there is. This pressing force is called "initial pressing force."

(Effects of the Invention) As described above, the present invention allows the seat packing and the metallic elastic member to be inserted into the approximate T-shaped groove provided in the valve body or the inner valve without being fixed, and the seat packing and the metallic elastic member to be inserted into the approximate T-shaped groove provided in the valve body or the inner valve. By shaping the member to make maximum use of fluid pressure and self-elastic force, its blocking performance is improved regardless of the direction of fluid flow. Disadvantages of having a sealing device,
That is, in the conventional sheet packing shown in FIG. 1, the drawback that there was a risk that the metallic elastic member serving as the reinforcing member would fall off could be completely eliminated. That is, in the device of the present invention, the metal elastic member 6 extends the outer flange portion 16 between the sheet packing 1 and the sheet packing presser 3 from the dogleg-shaped bent portion 17 to the outer end of the sheet packing 1. Due to this configuration, the outer flange portion 16 of the metal elastic member 6 is firmly held between the seat packing 1 and the seat packing presser 3, and there is no risk of the metal elastic member 6 falling off. Not at all. In the device of the present invention, the sealing surface 13, which is a part of the outer circumferential wall of the outer circumferential portion 28 of the sheet packing 1, is in close contact with only the portion of the outer circumferential inner wall surface of the approximate T-shaped groove that is closer to the sheet packing presser 3, The structure in which this close contact area does not change under any circumstances enhances the effect of preventing the metallic elastic member 6 from falling off. The outer flange portion 16 of the metal elastic member 6 covers the side wall of the outer peripheral wall 28 of the sheet packing 1 on the sheet packing pressing side, and the outer flange portion 16 of the metal elastic member 6 covers the upper portion 19. The sealing surface 1 of the outer peripheral part 28 of the seat packing 1 has the effect of increasing the rigidity of the
The initial pressure contact force against the outer peripheral inner wall surface 15 of No. 3 was maintained at all times, and a sufficient sealing effect could be achieved.

In the present invention, the metal elastic member having the above configuration is as follows:
Since the mechanical elastic force and restoring force of the seat packing are rationally reinforced, even if the fluid pressure decreases, the elastic force of the seat packing and the metal elastic member maintains the initial pressure on the inner valve and prevents the fluid from flowing. can be blocked. Furthermore, since the fluid pressure is effectively used, the seat packing can be prevented from being destroyed by concentrated loads, allowing for long-term continuous use.Furthermore, since the elastic member for reinforcement is made of metal, the seat packing can be easily used. It can be used up to the heat-resistant limit temperature of the synthetic resin that forms it.

[Brief explanation of drawings]

FIG. 1 is an enlarged sectional view showing an example of a conventional sealing device, FIG. 2 is an enlarged sectional view showing the configuration of an embodiment of the present invention, with the flow path opened, and FIG. 3 is an enlarged sectional view showing the flow path. 4 is a vertical sectional view showing another embodiment of the present invention applied to a butterfly valve; FIG. 5 is a sectional view taken along line a-a in FIG. Fig. 6 is an enlarged sectional view showing the state of the seat packing etc. when fluid pressure is applied in the left direction indicated by the arrow in the state shown in Fig. 3, and Fig. 7 shows the configuration of still another embodiment of the present invention. 8 is an enlarged cross-sectional view with the flow path open, and FIG. 8 is a cross-sectional view taken along the line b-b in FIG.
FIG. 9 is an enlarged longitudinal sectional view of the seat packing etc. in FIG. 2. 1 is a seat seal, 2 is a valve body, 3 is a seat seal holder, 4 is an inner valve, 5 is a valve seat surface, 6 is a metal elastic member, 7 is a screw, 8 and 8' are clearances,
9 is a first fluid pressure introduction chamber, 10 is a second fluid pressure introduction chamber, 11 is a contact surface to the valve seat surface, 12 is a protrusion limiting shoulder, 13 is a sealing surface, 14 is a protrusion, 15 is an outer peripheral inner wall surface, 16 17 is an outer flange portion, 17 is a dogleg-shaped bent portion, 18 is a lower piece portion, 19 is an upper piece portion, 20 is a T-shaped groove with an approximate cross section, 21 is a valve stem, 22 is a pin, 23 is a seal ring, and 24 is a Lever handle, 25 is pin, 26, 26' are fluid pressure introduction holes, 27 is the lower wall surface of the V-shaped groove of the seat packing, 28 is the outer periphery,
29 is the inner circumference.

Claims (1)

[Scope of Claims] 1. An approximately T-shaped groove in cross section is formed around the flow path of the valve body, and the valve body and the seat packing retainer are provided with mutually opposing protrusions at the groove outlet, and the groove can be engaged with the protrusions. A synthetic resin sheet packing having an approximately T-shaped cross section with a protrusion limiting shoulder is formed into an annular shape and is loosely fitted into the annular approximately T-shaped groove, and the synthetic resin sheet packing has a seat packing pressing side. , an approximate V-shaped groove is formed in the seat seal with an opening in the direction of the seat seal presser through a clearance between the seat seal and the seat seal presser, and a dog-shaped groove inscribed in the V-shaped groove is formed. A first fluid pressure introducing chamber is provided by inserting an annular metal elastic member having a curved portion, and
On the opposite side, a second fluid pressure introduction chamber is provided between the seat gasket and the valve body through a clearance, and the inner valve is in contact with the portion of the sheet gasket that protrudes into the flow path so as to be able to freely come into contact with and separate from the valve body. In the sealing device, the sealing surface, which is a part of the outer circumferential wall of the seat seal, is in close contact with a portion of the outer circumferential inner wall surface of the approximate T-shaped groove near the seat seal presser, and the second fluid pressure is introduced. A small gap constituting a part of the chamber exists between the outer circumferential inner wall surface only at a portion farthest from the seat packing holder, and the annular metal elastic member is arranged between the seat packing and the seat packing holder. 1. A valve sealing device, characterized in that an outer flange portion is provided between said doglegged bent portion and an outer end portion of said seat packing.